Dark and luminous matter in the outer halos of elliptical galaxies

椭圆星系外晕中的暗物质和发光物质

• 批准号: 41898745
• 负责人: Professor Dr. Ortwin Gerhard
• 金额: --
• 依托单位: Max-Planck-Institut für extraterrestrische Physik (MPE)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/41898745?language=en
• 关键词: Dark; luminous; matter; outer; halos

Much of the fossil record of elliptical galaxy formation is hidden at large radii, where dynamical times are long, dark matter dominates, and most of the angular momentum is expected to reside. The only tracers for studying stellar kinematics beyond a few effective radii are planetary nebulae (PNe). Results from a survey of PN kinematics in the outer halos of elliptical galaxies have revealed an unexplained dichotomy in their dynamics, which is not apparent from photometry alone. Dynamical modeling has also shown that several of these systems either contain little dark matter within five effective radii, or that their stellar halos are characterized by extreme radial orbit anisotropy. By contrast, modeling of X-ray bright systems is revealing massive and dense dark matter halos, and a strongly radially biassed outer distribution of stars. In order to understand better what lies behind these results, we propose to construct dynamical models for a well-chosen sample of both X-ray bright and X-ray faint ellipticals. The goal of the project is to determine the angular momentum content, orbital structure, and dark matter content of ellipticals as a function of luminosity and environment, and thereby obtain the necessary information for distinguishing between the different merger processes at work in the formation of elliptical galaxies.

椭圆星系形成的大部分化石记录都隐藏在大半径内，那里的动力学时间很长，暗物质占主导地位，预计大部分角动量都存在。除了几个有效半径以外，研究恒星运动学的唯一示踪剂是行星星云(PNE)。对椭圆星系外晕的Pn运动学的调查结果表明，它们的动力学存在无法解释的二分性，仅从光度学角度看并不明显。动力学模型还表明，这些系统中的几个要么在五个有效半径内包含很少的暗物质，要么它们的恒星晕具有极大的径向轨道各向异性。相比之下，X射线明亮系统的模拟揭示了大质量和密集的暗物质晕，以及强烈的辐射偏向的恒星外部分布。为了更好地理解这些结果背后的原因，我们建议对X射线亮椭圆体和X射线弱椭圆体的精选样本建立动力学模型。该项目的目标是确定椭圆的角动量含量、轨道结构和暗物质含量作为光度和环境的函数，从而获得必要的信息，以区分在椭圆星系形成过程中起作用的不同合并过程。

项目成果

Unravelling the origins of S0 galaxies using maximum likelihood analysis of planetary nebulae kinematics

利用行星状星云运动学的最大似然分析揭示 S0 星系的起源

• DOI: 10.1111/j.1365-2966.2011.18429.x
• 发表时间: 2011
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Cortesi;Merrifield;Arnaboldi;Gerhard;Martinez-Valpuesta;Coccato;Bamford;Napolitano;Douglas;Romanowsky;Kuijken;Capaccioli;Freeman
• 通讯作者: Freeman

Dearth of dark matter or massive dark halo? Mass-shape-anisotropy degeneracies revealed by nmagic dynamical models of the elliptical galaxy NGC 3379

• DOI: 10.1111/j.1365-2966.2009.14553.x
• 发表时间: 2008-04
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: F. Lorenzi;O. Gerhard;L. Coccato;M. Arnaboldi;M. Capaccioli;N. Douglas;K. Freeman;K. Kuijken;M. Merrifield;N. Napolitano;E. Noordermeer;A. Romanowsky;V. Debattista

UNIFYING A BOXY BULGE AND PLANAR LONG BAR IN THE MILKY WAY

• DOI: 10.1088/2041-8205/734/1/l20
• 发表时间: 2011-05
• 期刊: The Astrophysical Journal Letters
• 作者: I. Martinez-Valpuesta;O. Gerhard

Dark matter content and internal dynamics of NGC 4697 : NMAGIC particle models from slit data and planetary nebula velocities

• DOI: 10.1111/j.1365-2966.2008.12905.x
• 发表时间: 2008-02
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: F. Lorenzi;O. Gerhard;R. Saglia;N. Sambhus;V. Debattista;M. Pannella;R. G. M. Garching;Astron. Inst.;U. Basel;Centre for Astroph.;U. C. Lancashire;Ifa;U. Hawaii

Steepening mass profiles, dark matter and environment of X-ray bright elliptical galaxies

• DOI: 10.1111/j.1365-2966.2010.17417.x
• 发表时间: 2010-07
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: P. Das;O. Gerhard;E. Churazov;I. Zhuravleva